Best and most reliable way to easily remove duplicate contacts from a VCF file is to use an offline vCard duplicate remover like the
Softaken vCard Duplicate Remover. Because this is an offline tool, it never leaks your contact information and quickly runs on all windows. The tool easily scans duplicate entries based on names, phone numbers, emails, images, etc. And maintain all the original file formats. Additionally, the software supports batch processing, so you can rapidly remove so many VCF duplicate entries in one process. This expert vCard duplicate remover offers a best user-friendly dashboard, so new users can also operate this software. A free demo is available.
